This invention is directed to a machine for peeling krill which are defined as euphausiids which are small, shrimp-like organisms. They are distributed around the world in both shallow and deep pelagic waters. There are 85 recognized species of krill.
Most likely the highest value products obtainable from krill will be based on shell-free intact tail meats. The peeling of krill by shrimp-peelers has been undertaken with conventional shrimp peeling machines such as shown in U.S. Pat. Nos. 2,755,501; 2,778,055; 2,781,544; 2,976,564; 3,070,833 and 3,383,734 which employ contra-rotating parallel rollers parallel to the path of travel of raw material through the machine. Results while encouraging have been far from satisfactory with regard to yield and capacity within a given cubical space. The parallel rolls are inclined. The raw material (krill) is fed automatically to the peeler where the rapidly alternating contra-rotating inclined parallel rollers pull off the heads, carapace, legs and feelers. The action is assisted by copious quantities of flowing water.
One of the main points of distinction of the machine of the present invention over the machines of the above identified patents is the fact that the peeling rolls of the present machine have their major axes transverse to the path of flow of krill through the machine. Positioning the peeling rolls with their axes transverse to the path of flow of the raw material over the peeling rolls broadly is shown in U.S. Pat. Nos. 2,429,828; 3,740,795 and 2,832,092 however these patents do not teach the krill feeding and water conveying techniques of the present machine which lend themselves to shipboard or land based operation.
The extremely poor keeping quality of krill seems to indicate that processing take place within three or four hours after catching.
The catching and processing of krill is best shown and described in THE UTILIZATION OF KRILL, by C. J. Grantham, published in FOOD AND AGRICULTURE ORGANIZATIONS OF THE UNITED NATIONS, UNITED DEVELOPMENT PROGRAMME, ROME 1977 and THE ANTARTIC KRILL RESOURCE: PROSPECTS FOR COMMERCIAL EXPLOITATION, TETRA TECH INC., Pasadena, Ca., prepared for Dept. of State, Washington, D.C. PB-280 791 Feb. 1978.
One object of the invention is to provide a krill peeling machine of high capacity which occupies a small amount of cubical space for use aboard seagoing vessels.
Another object of the invention is to provide a krill peeling machine which uses gravity rather than conveyors to carry the krill from the peeling stage to the cleaning stage in a single machine.
Another object of the invention is to provide a krill peeling machine which produces the maximum amount of edible meat from a given quantity of shell-on krill.
Another object of our invention is to provide a krill longitudinal guide means spaced transversely along the major axes of the transversely disposed inclined peeling rolls to maintain a uniform layer of krill over the peeling nips independent of the rate of water employed as a peeling lubricant and conveyor. In the instance of a shipboard or vessel installation the longitudinal guide means are foraminous to permit the water to flow transversely of the path of peeling flow to avoid waving of the krill to the side of the machine in the direction of roll of the vessel.
A still further object of our invention is the provision of a krill leveling device for use with a bank of transversely positioned oscillating peeling rolls which leveling device may be vertically raised and lowered and the speed of which can increase or decrease the quantity of krill supplied to the bank of peeling rolls necessary to provide a uniform mat of krill to be subjected to the peeling nips of the bank of peeling rolls.
Our invention also provides a plural bank or tier arrangement with loading chutes that subject the krill to the peeling action of only one bank of peeling rolls prior to being subjected to a final bank of cleaning rolls. The angle of incline of each bank of peeling rolls is from 20.degree. to 30.degree. below the horizontal. Preferably the inclination should be of the order of 26.degree..